Soil tamping device



1965 c. R. GLASS 3,199,424

SOIL TAMPING DEVICE Filed Sept. 21, 1962 5 Sheets-Sheet l INVENTOR.

CATZL E. G-LNsS ATTORN Y Aug. 10, 1965 c. R. GLASS SOIL TAMPING DEVICE 5Sheets-Sheet 2 Filed Sept. 21, 1962 fig-4L 1N VENTOR.

W4 L s 68) 71 CAQL. i2 GLAS$ -rw-oewevs 0, 1965 c. R. GLASS 3,199,424

SOIL TAMPING DEVICE Filed Sept. 21, 1962 3 Sheets-Sheet 3 INVENTOR. CAraL 2 G LA$$ ATTORNEYS United States Patent 3,199,424 SGIL TAMIING DEVICECarl R. Glass, 203 Peincianna Qircle, lifissirnrnee, Fla. Fitted Sept.21, 1962, Ser. No. 225,176 8 Claims. (@l. 94-48) This invention relatesto a tamping or impacting machine, such as used for conditioning soil,or other granular masses. Present-day methods and machines have longsince displaced the primitive tampers, or rams, delivering individualblows through manual effort, and in particular, the system usingimbalanced, revolving weights has commanded attention, as havingcapabilities both of cyclic impact and of self-propulsion, both flowingfrom the action of the eccentric weights. In the main, devices of thissort which have been proposed bear several points of similarity, onewith another, as to the basic combination of elements, but theresemblance is more or less superficial, since the mechanical principlesinvolved in the system are sufficiently involved that minor departuresmay well measure up to the difference between success and failure, or todifferences in etiiciency or performance which are critical as toacceptability or rejection.

For example, one such device envisages an internal combustion engine asa source of power, mounted on the tamping machine and having a drivingconnection with a shaft having one or more eccentric weights.Considerations of compactness of design almost require that such anengine be mounted vertically above the eccentric element, which resultsin a second eccentric system unfavorably located in spaced relation tothe working eccentric, which introduces complications, and lowers theefiiciency. The same would be true even if the engine were located closeto ground level. In recognition of this, it has been proposed to providetiming means to guarantee synchronism between the two systems, but thisrepresents a minor compromise at best, and leaves the main difficultiesunremedied.

According to the present invention, this one particular difficulty hasbeen remedied by employing an electric motor as a prime mover, or, todescribe it in terms related to the underlying problem, a power sourceof uniform rotational inertia. It is therefore a general object of theinvention to provide a tamper comprising an eccentric system of compactform and simplicity of structure, and which is free from counteracting,extraneous, eccentric components.

On the other hand, although electric motors have been proposed for usein tempers, the working eccentrics have been included on the motorshaft, with a consequently low position of the center of gravity of thesystem, and a resultant loss of sensitivity of equilibrium.

It is, therefore, a further object of the invention to overcome thissecond difiiculty, and, in particular, to accomplish this result bymeans of a non-eccentric prime mover, at a high level, with a drivemeans to a working eccentric, located at a low level.

In addition to the foregoing, it is an object to locate the prime moverand eccentric in a mounting, in relative positions with respect to eachother and to the mounting, which further enhances the efficiency of theorganization, as will be detailed hereinafter.

The objects also include the provision of a device which is of minimumcomplexity, yet durable, and certain of operation, and which is easy offabrication, assembly, repair and maintenance, and also low in cost.

These and other ends, which will be apparent, are attained by thepresent invention, a preferred form of which is described in thefollowing specification, as illustrated in the drawings, in which:

FIGURE 1 is a perspective view of the tamping machime in workingposition,

FIGURE 2 is a fragmentary view, in side elevation, of the lower part ofthe machine, in tilted position, for transport,

FIGURE 3 is a bracketed view, in perspective, showing the parts of thetransport dolly unit, in exploded form, with the wheel axis shown on astaggered line,

FIGURE 4 is a top plan view of the main housing of the tamper, as seenalong the plane of the staggered line 44 of FIGURE 1, showing a sectionthrough the tubular guide shaft,

FIGURE 5 is a transverse, vertical, sectional view through the mainhousing, taken on the plane of the staggered line 55 of FIGURE 1,

FIGURE 6 is a longitudinal, vertical, sectional view through thehousing, taken on the plane of the staggered line 6-6 of FIGURE 1,

FIGURE 7 is a sectional view of a detail of the flexible, handlecoupling, taken on the plane of the line 7-7 of FIGURE 1,

FIGURE 8 is a perspective view of the shaft carrying the eccentricweight, apart from the assembly, and

FIGURE 9 is a sectional view through the shaft and its eccentric, takenon the plane of the line 9-9 of FIG- URE 8.

Referring to the drawings by characters of reference, there is shown, inFIGURE 1, a complete tamping assembly, comprising a ground-dwellinghousing, indicated as a whole by the numeral 10, and an upright,manipulating handle 12, connected to a horizontally disposed section 14,through a resilient coupling 16. The latter, which serves to absorb theshocks of the vibrations in the tamper unit It comprises an elbow-shapedsection 18, (FIG- URE 7) of tough, resilient material, such as nylonplastic, or a tough stock of rubbery material, reinforced if necessary,to which is bonded or otherwise secured, a lower, angle plate 20,secured by bolts 22 to a transverse platform 24 on the top of the handlesection 12, and an upper, angle plate 25, secured by bolts 23 to aflattened end on the tubular handle section 14. At its lower end, thehandle section 12 is swingably mounted on a bracket 30, carried on theouter surface of the rear wall 32 of housing 10, by means of a pivotbolt 34, and the rearward swing of the handle is limited by a bolt 36,selectively engageable in aligned pairs of bores 38 in the walls ofbracket 30. The most convenient setting of the handle angle will beselected by the operator in accordance with his own technique, and inview of the character of operations in any particular job, and thenature of the work, in general.

The working characteristics of the tamper depend, almost wholly, on theconstruction and arrangement of housing It and its contents, the severalparts of which are important, each in itself, and in relation to otherparts, in the achievement of the over-all, end result. One primeconsideration is compactness in the container portion of the housing,coupled with a relatively expansive tread, or ground-engaging portion.That is to say, the portion which encloses the eccentric unit, is nobigger than need be to house this unit, so that inertial effect whichwould tend to counteract the output of the eccentric, and thus putsevere restrictions on it, and lower its efficiency, are minimized. Forsimilar reasons, the eccentric unit itself is kept within a moderaterange of eccentricity, suited to the demands of the machine.

Thus, the housing It comprises a suitable box unit of rectangularconfiguration, having a forward wall 40, parallel to rear wall 32, thetwo walls being of equal length and being substantially elongate in ahorizontal direction. The housing has a pair of end walls 42, 44,joining the front and rear walls, and a top plate or cover 46, dwellingon the top edges of the four sides, and projecting beyond the front andrear walls, is secured by bolts as to angle brackets 5b, carried onfront and rear walls 32, 4b, with one leg flush with the top edgesthereof.

A motor 52, is secured by bolts 54 to cover plate 45, being spaced fromthe cover by washer tubes 56, and a plate 55. An elongate slot (it) inthe cover plate as provides access to the interior of the box by a belt62, mounted on a pulley 64- on the output shaft 66 of motor 52.

The bottom of housing it) is closed off by the groundengaging, tamperplate 68, welded to the bottom edges, and which is bent into three,distinct, planar sections 70, 72, 74, rectangular in shape, as definedby two, parallel lines of bend, 7d, 75. The short, rearward section isperpendicular to the rear wall 32, and extends a short distance on eachside thereof, the line of bend, '76, being located somewhat short ofcenter of the housing. The middle section 68, inclined at a substantialangle to section 70 completes the span of the lower opening of thehousing, and extends substantially beyond front wall From the secondline of bend, 78, the bottom plate continues, at a substantial angle tosection 72, and for a substantial distance. The end walls 42, 44- areshaped to conform with the ground plate, and the sides of the latterextend somewhat outwardly of these walls.

Within the housing, the eccentric rotor comprises a shaft 8% with itsreduced ends 82 journalled in suitable bearing blocks 84, secured bybolts 36 on the inner faces of end walls 42, 44, and the shaft isprovided with a pulley 83, which is engaged by belt 62 from the motor.

Shaft 8b is provided with an offset weight 9%), of solid, cylindricalform, secured as by welding to the shaft, medially thereof, in verynearly tangential relation, but which is preferably flattened, orgrooved, as at 91, along the line of contact, for greater holding power.In the preferred form shown the diameter of cylinder 90 is about twicethat of shaft 80.

The several parts are shown in relative proportions which represent apreferred embodiment of a proved form of the device, and it will benoted that the width of the housing, between front and rear walls 4t),32, is sized to provide minimized clearance between the eccentric Weight9% and the walls.

FTGURE 5 shows the machine in a position of rest, with mid-section 72 ofthe ground plate horizontal. The arrangement is such that there is adistinct forward tilt of the housing, but the system is in equilibrium,because a vertical line from the center of gravity of the system, (whichis somewhere along a plane through the axis of shaft 8%? and that of themotor) passes through the ample, center section 72 of the base plate.However, both by virtue of the appreciable tilt of this axial plane, andthe elevation of the motor 52, the system is biased into proximity to aposition favoring forward tipping, and this is attained, intermittentlydue to the action of the eccentric This action results from a tendencyof the eccentric to rotate on an axis other than that of shaft 80. Dueto this, the system is urged downward during one phase of rotation, andexperiences an upward lift during another. Thus, it hops along, asassisted by its forward inclination, and during this progress, thesystem rocks about the ground plate, with forward section 74 preparingthe ground in advance, preliminarily, with center section 72 nextdropping into place, after a hop, to provide a main tamping action, andwith rear section '79 providing a follow-up to the tamping, as thenatural period of vibration, or rocking, of the system causes it to rockbackward on this section.

In the over-all results, some of the main contributing factors are theconfinement of eccentric action to the lower part of the system, theprovision of an upwardly located prime mover, which provides a degree oftopheaviness, without counteracting eccentric action, and the provisionof the three-part tamper plate, with the main, central portion angularlyrelated to the common plane of the centers of gravity, and expansiveenough to provide normal, rest equilibrium, and the two, end rockersections in the tamper plate.

Another important innovation is the use of a cylindrical eccentricweight. Although it is common to employ a sector-form of eccentric,centered on the axis of the shaft, analysis will show that the tangentcylinder provides a moment of inertia which is substantially equal tothat of a sector of equivalent cross-sectional area, and no greaterangular extent relative to the shaft axis. This result has at least twoimportant benefits; first, it is easily fabricated by cutting sectionsfrom round stock, and second, what is more important, it locates thecenter of mass of the eccentric system closer to the shaft axis than inthe case of the sector form, with a resultant reduction in amplitude ofvibrations, and hence smoother and more controllable operations. Inother words, the operation is improved, without sacrifice of the amountof available, working energy.

For ready transport, as between one work site and another, the machineis conveniently provided with a dolly, which is so disposed as to be outof the way during tamping operations, but is readily brought into use bysimple tilting of the machine. As shown in FIGURES 2 and 3, the dollycomprises a split, cylindrical tube 92, received on upright handlesection 12, and having two pairs of cars 94, receiving clamping screws96. An oblique strut 98, with one end secured longitudinally to tube 92,has its other end secured peripherally to a horizontal bearing sleeve10th, in which is journalled an axle m2, carrying a pair of rubber-tiredwheels 1%, supplied with washers 106 and retained by cotter pins ltld.As seen in FIG- URE 2, when the inclination of handle 12 is lowered, thesystem rocks about the wheel axis, resulting in the lifting of thetamper plate from the ground, and thus enabling transport of the machineon the supporting wheels 104.

While a certain, preferred embodiment has been shown and described,various modifications will be apparent, in the light of this disclosure,and the invention should not, therefore, be deemed as limited, exceptinsofar as shall appear from the spirit and scope of the appendedclaims.

I claim:

1. A vibrating machine, for earth tamping and the like, comprising ahousing with four, rectangularly disposed Walls including front and rearwalls, and parallel end walls, said walls having co-planar, upper edges,and a cover plate secured to said housing in covering relation to saidupper edges, said front wall being less in depth than said rear wall,and the bottom edges of said end walls each comprising two angularlydisposed portions, one portion perpendicular to said rear wall, andextending inwardly therefrom, for a distance less than half the width ofthe end face, and the other portion extending from the said one portionto said front wall, a bottom plate in three angularly disposed sections,secured to the bottom edges of said walls, and extending outwardly ofsaid end walls, and having a first section coinciding with said oneportion, and extending outwardly of said rear wall, a second sectioncoinciding with said other portion, and extending substantially beyondsaid front wall, and a third section disposed at an angle to said secondsection, and inclined toward the top of said housing, a motor carried bysaid coverplate, outwardly of said housing, a shaft within said housing,journalled to said end walls generally medially of the distance betweensaid front and rear walls, and medially of the depth of said front wall,a driving connection between said motor and said shaft, and an eccentricweight carried by said shaft, medially of the length thereof, andcomprising a solid right circular cylinder, having a longitudinal groovemating with the periphery of said shaft, and secured thereto, a handlecomprising a first portion, pivoted to said housing, and means to adjustthe inclination of said first portion, a second portion disposedtransversely to said first portion, and a resilient coupling connectingsaid portions.

2. A device as in claim 1, said resilient coupling comprising agenerally arcuate section of plastic material, and metallic angle platescarried by the said handle portions, and bonded to opposite faces ofsaid material.

aloe tea 3. A vibrating machine, for earth tamping and the like,comprising a housing with four, rectangularly disposed wails includingfront and rear walls, and parallel end walls, said walls havingco-planar, upper edges, and a cover plate secured to said housing incovering relation to said upper edges, said front wall being less indepth than said rear wall, and the bottom edges of said end walls eachcomprising two angularly disposed portions, one portion perpendicular tosaid rear wall, and extending inwardly therefrom, and the other portionextending from the said one portion to said front wall, a bottom platein three angularly disposed sections, secured to the bottom edges ofsaid walls, and having a first section coinciding with said one portion,and extending outwardly of said rear wall, a second section coincidingwith said other portion, and extending substantially beyond said frontwall, and a third section disposed at an angle to said second section,and inclined toward the top of said housing, a motor carried by saidcover plate, outwardly of said housing, a shaft within said housing,journalled to said end walls, a driving connection between said motorand said shaft, and an eccentric weight carried by said shaft, mediallyof the length thereof, and comprising a solid right circular cylinder,having a longitudinal groove mating with the periphery of said shaft,and secured thereto, a handle comprising a first portion, pivoted tosaid housing, and means to adjust the inclination of said first portion,a second portion disposed transversely to said first portion, and aresilient coupling connecting said portions.

4. A vibrating machine, for earth tamping and the like, comprising ahousing with four, rectangularly disposed Walls including front and rearwalls, and parallel end Walls, said walls having co-planar, upper edges,and a cover plate secured to said housing in covering relation to saidupper edges, said front wall being less in depth than said rear wall,and the bottom edges of said end walls each comprising two angularlydisposed portions, one portion perpendicular to said rear wall, andextending inwardly therefrom, and the other portion extending from thesaid one portion to said front Wall, a bottom plate in three angularlydisposed sections, secured to the bottom edges of said walls, and havinga first section coinciding with said one portion, and extendingoutwardly of said rear wall, a second section coinciding with said otherportion, and extending substantially beyond said front wall, and a thirdsection disposed at an angle to said second section, and inclined towardthe top of said housing, a motor carried by said cover plate, outwardlyof said housing, a shaft Within said housing, journalled to said endwalls, a driving connection between said mot-or and said shaft, and aneccentric weight carried by said shaft, medially of the length thereof,and comprising a cylinder secured to the shaft in approximatelytangential relationship, a handle comprising a first portion, pivoted tosaid housing, and means to adjust the inclination of said first portion,a second portion disposed transversely to said first portion, and aresilient coupling connecting said portions.

5. A vibrating machine, for earth tamping and the like,

comprising a housing with four, rectangularly disposed walls includingfront and rear walls, and parallel end walls, said walls havingco-planar, upper edges, and a cover plate secured to said housing incovering relation to said upper edges, said front wall being less indepth than said rear wall, and the bottom edges of said end walls eachcomprising two angulariy disposed portions, one portion perpendicular tosaid rear wall, and extending inwardly therefrom, and the other portionextending from the said one portion to said front wall, a bottom platein three angularly disposed sections, secured to the bottom edges ofsaid walls, and having a first section coinciding with said one portion,and extending outwardly of said rear wall, a second section coincidingwith said other portion, and extending substantially beyond said frontwall, and a third section disposed at an angle to said second section,and inclined toward the top of said housing, a motor carried by saidcover plate, outwardly of said housing, a shaft within said housing,journalled to said end walls, a driving connection between said motorand said shaft, and an eccentric weight carried by said shaft, mediallyof the length thereof, and comprising a cylinder secured to the shaft inapproximately tangential relationship.

6. A vibrating machine for earth tamping and the like, comprising ahousing with a front wall, a rear wall, and two end walls, a cover plateon the top edges of said walls, and perpendicular thereto, a motorcarried by said top plate, a bottom plate secured to the lower edges ofsaid walls and bent along two parallel fold lines to form three sectionsdefining two dihedral angles, including a first section parallel to saidcover plate, and extending on both sides of said rear wall, a secondsaid section contiguous with said first section and inclined at apositive angle thereto, and extending on both sides of said front wall,and a third section contiguous with, and inclined at a positive angle tosaid second section, an eccentric rotor journalled in said end walls,and a driving connection between said motor and said rotor, said secondsection of said bottom plate being so located as to be intersected by aperpendicular from the cent-er of gravity of the shaft and motorcombination.

7. A device as in claim 6, said eccentric rotor comprising a concentricshaft, and a cylindrical block secured to said shaft in approximatelytangential relation.

3. A device as in claim '7, said cylindrical block having a diameterapproximately twice that of said shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,542,979 2/51Barnes 94-48 2,596,281 5/52 OBrien 74-87 2,644,379 7/53 Lowe 94-482,737,094 3/56 Jackson 94-48 2,856,828 10/58 Brown 94-48 2,894,435 7/59Brown 94-48 CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

1. A VIBRATING MACHINE, FOR EARTH TAMPING AND THE LIKE, COMPRISING AHOUSING WITH FOUR, RECTANGULAR DISPOSED WALLS INCLUDING FRONT AND REARWALLS, AND PARALLEL END WALLS, SAID WALLS HAVING CO-PLANAR, UPPER EDGES,AND A COVER PLATE SECURED TO SAID HOUSING IN COVERING RELATION TO SAIDUPPER EDGES, SAID FRONT WALL BEING LESS IN DEPTH THAN SAID REAR WALL,AND THE BOTTOM EDGES OF SAID END WALLS EACH COMPRISING TWO ANGULARLYDISPOSED PORTIONS, ONE PORTION PERPENDICULAR TO SAID REAR WALL, ANDEXTENDING INWARDLY THEREFROM, FOR A DISTANCE LESS THAN HALF THE WIDTH OFTHE END FACE, AND THE OTHER PORTION EXTENDING FROM THE SAID ONE PORTIONTO SAID FRONT WALL, A BOTTOM PLATE IN THREE ANGULARLY DISPOSED SECTIONS,SECURED TO THE BOTTOM EDGES OF SAID WALLS, AND EXTENDING OUTWARDLY OFSAID END WALLS, AND HAVING A FIRST SECTION COINCIDING WITH SAID ONEPORTION, AND EXTENDING OUTWARDLY OF SAID REAR WALL, A SECOND SECTIONCOINCIDING WITH SAID OTHER PORTIN, AND EXTENDING SUBSTANTIALLY BEYONDSAID FRONT WALL, AND A THIRD SECTION DISPOSED AT AN ANGLE TO SID SECONDSECTION, AND INCLINED TOWARD THE TOP OF SAID HOUSING, A MOTOR CARRIED BYSAID COVERPLATE, OUTWARDLY OF SAID HOUSING, A SHAFT WITHIN SAID HOUSING,JOURNALLED TO SAID END WALLS GENERALLY MEDIALLY OF THE DISTANCE BETWEENSAID FRONT AND REAR WALLS, AND MEDIALLY OF THE DEPTH OF SAID FRONT WALL,A DRIVING CONNECTION BETWEEN SAID MOTOR AND SAID SHAFT, AND AN ECCENTRICWEIGHT CARRIED BY SAID SHAFT, MEDIALLY OF THE LENGTH THEREOF, ANDCOMPRISING A SOLID RIGHT CIRCULAR CYLINDER, HAVING A LONGITUDINAL GROOVEMATING WITH THE PERIPHERY OF SAID SHAFT, AND SECURED THERETO, A HANDLECOMPRISING A FIRST PORTION, PIVOTED TO SAID HOUSING, AND MEANS TO ADJUSTTHE INCLINATION OF SAID FIST PORTION, A SECOND PORTION DISPOSEDTRANSVERSELY TO SAID FIRST PORTION, AND A RESILIENT COUPLING CONNECTINGSAID PORTIONS.